Display panel and display device
By introducing a structure that combines a temperature control substrate with a driving backplane into the OLED display panel, and using thermocouples to adjust the cooling capacity in real time, the problems of uneven brightness and image retention are solved, achieving brightness uniformity and efficient and accurate cooling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEFEI XINSHENG OPTOELECTRONICS TECH CO LTD
- Filing Date
- 2024-01-16
- Publication Date
- 2026-06-19
Smart Images
Figure CN117727274B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of display technology, and more specifically, to a display panel and a display device. Background Technology
[0002] OLED (Organic Light Emitting Diode) display panels have advantages such as self-illumination, wide color gamut, high contrast, flexibility, and high response, and have broad application prospects. However, current display panels may have local brightness deviations from the standard when displaying images, the uniformity of the image still needs to be improved, and image retention is prone to occur in some areas.
[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0004] This disclosure provides a display panel and display device that can improve the uniformity of the image and reduce image retention.
[0005] According to one aspect of this disclosure, a display panel is provided, including a driving backplate, a light-emitting device, and a temperature control substrate, wherein the driving backplate is disposed between the light-emitting device and the temperature control substrate; the temperature control substrate includes a temperature control element having a cooling end and a heat dissipation end distributed in a direction away from the driving backplate.
[0006] The driving backplane includes a pixel circuit, which includes a driving transistor, a writing circuit, a storage circuit, and a temperature control circuit.
[0007] The first electrode of the driving transistor is used to receive a first power signal, and the second electrode of the driving transistor is connected to the first electrode of the light-emitting device, the second electrode of the light-emitting device being used to receive a second power signal; the writing circuit is connected to the gate of the driving transistor and is used to transmit a data signal to the gate of the driving transistor in response to a scan signal; the storage circuit is connected to the gate and the second electrode of the driving transistor; the temperature control circuit is used to receive a third power signal and is connected to the temperature control element and the second electrode of the driving transistor, the temperature control element also being used to receive a fourth power signal;
[0008] The cooling capacity of the temperature control element is positively correlated with the voltage of the data signal.
[0009] In one exemplary embodiment of this disclosure, the temperature control substrate includes a first substrate and a second substrate sequentially distributed along a direction close to the drive back plate, and the temperature control element is disposed between the first substrate and the second substrate;
[0010] The temperature control element is a thermocouple, and the temperature control element includes a first connecting electrode, a second connecting electrode, a connecting bridge, a first thermocouple using an N-type semiconductor and a second thermocouple using a P-type semiconductor.
[0011] The first connecting electrode and the second connecting electrode are disposed on the side of the first thermocouple and the second thermocouple close to the first substrate, and the first connecting electrode is connected to the first thermocouple, and the second connecting electrode is connected to the second thermocouple; the connecting bridge is disposed on the side of the first thermocouple and the second thermocouple close to the second substrate, and connects the first thermocouple and the second thermocouple.
[0012] In one exemplary embodiment of this disclosure, the temperature control substrate includes a plurality of temperature control units, one of the temperature control units overlapping with a pixel circuit and a light-emitting device; one temperature control unit includes a plurality of temperature control elements, and the temperature control elements of the same temperature control unit are connected in series.
[0013] In one exemplary embodiment of this disclosure, the writing circuit includes a writing transistor, the temperature control circuit includes a temperature control transistor, and the storage circuit includes a storage capacitor;
[0014] The first terminal of the write transistor is used to receive the data signal, the second terminal of the write transistor is connected to the gate of the drive transistor, and the gate of the write transistor is used to receive the scan signal;
[0015] The first plate of the storage capacitor is connected to the gate of the driving transistor, and the second plate is connected to the second terminal of the driving transistor.
[0016] The first electrode of the temperature control transistor is used to receive the third power supply signal, the second electrode of the temperature control transistor is connected to the first connection electrode of the temperature control element, and the gate of the temperature control transistor is connected to the second electrode of the driving transistor.
[0017] The pixel circuit also includes a sensing transistor, the first terminal of which is connected to the second terminal of the driving transistor. The second terminal of the sensing transistor is used to output the signal of the second terminal of the driving transistor, and the gate of the sensing transistor is used to receive a sensing control signal.
[0018] In one exemplary embodiment of this disclosure, the drive backplane includes:
[0019] A semiconductor layer is disposed on the side of the second substrate away from the first substrate, and includes the active portions of the driving transistor, the writing transistor, the sensing transistor, and the temperature control transistor;
[0020] A gate insulating layer covering at least a portion of the semiconductor layer;
[0021] A gate layer is disposed on the surface of the gate insulating layer away from the first substrate, and includes the gates of the driving transistor, the writing transistor, the sensing transistor, and the temperature control transistor;
[0022] Interlayer dielectric layer, covering the gate layer;
[0023] The source / drain layer is disposed on the surface of the interlayer dielectric layer away from the first substrate;
[0024] A planarization layer covers the source / drain layer; the light-emitting device is disposed on the surface of the planarization layer away from the first substrate.
[0025] In one exemplary embodiment of this disclosure, the second power signal and the fourth power signal are the same.
[0026] In one exemplary embodiment of this disclosure, the display panel has a display area and a peripheral area located outside the display area; the driving backplane includes a power line, a first power bus and a second power bus; the first power bus is used to transmit the first power signal, and the second power bus is used to transmit the second power signal and the fourth power signal;
[0027] The power line is at least partially located in the display area and connected to the first electrode of the driving transistor; the first power bus and the second power bus are located in the peripheral area, and the power line is connected to the first power bus, while the second electrode of the light-emitting device and the second connection electrode of the temperature control element are connected to the second power bus.
[0028] In one exemplary embodiment of this disclosure, the drive backplane further includes a third power bus located in the peripheral area, the third power bus being used to transmit the third power signal, and the first terminal of the temperature control transistor being connected to the third power bus.
[0029] In one exemplary embodiment of this disclosure, the temperature control substrate further includes:
[0030] An insulating filler layer is filled between the first substrate and the second substrate; the first and second thermocouples of the temperature control element are embedded in the insulating filler layer.
[0031] According to one aspect of this disclosure, a display device is provided, comprising the display panel described in any of the preceding claims.
[0032] The present disclosure of the display panel and display device, for a pixel circuit, can control the conduction of the driving transistor through a data signal. Under the action of the first power signal and the second power signal, a current is generated through the light-emitting device, causing the light-emitting device connected to the driving transistor to emit light, thereby realizing the display of an image. In this process, the voltage of the data signal is positively correlated with the voltage of the second terminal of the driving transistor, the voltage of the second terminal of the driving transistor is positively correlated with the current of the light-emitting device, and the current is positively correlated with the brightness of the light-emitting device and the heat generated by the light emission, so that the voltage of the data signal is positively correlated with the brightness and heat of the light-emitting device.
[0033] Meanwhile, the signal at the second electrode of the driving transistor can turn on the temperature control circuit. Under the action of the third and fourth power signals, the cooling end of the temperature control element can cool down the display panel in the corresponding area, and the heat dissipation end dissipates heat. In this process, the cooling capacity of the temperature control element is controlled by the current passing through the temperature control circuit, and this current is controlled by the voltage at the second electrode of the driving transistor, and then by the voltage of the data signal, so that the cooling capacity of the temperature control element is positively correlated with the voltage of the data signal.
[0034] When displaying images, areas with higher brightness require greater cooling capacity from the temperature control element, resulting in stronger cooling. Conversely, areas with lower brightness require less cooling capacity, leading to weaker cooling. This ensures more uniform temperature distribution across areas of varying brightness, preventing localized overheating that could cause brightness deviations from the standard and reducing or eliminating localized image retention. Furthermore, the cooling capacity of the temperature control element can be adjusted in real-time via data signals, eliminating the need to specifically detect the temperature of the light-emitting device and calculate the cooling capacity. This makes cooling more timely and precise.
[0035] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description
[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.
[0037] Figure 1 This is a top view of one embodiment of the display panel of this disclosure.
[0038] Figure 2 This is a schematic diagram of the pixel circuit in one embodiment of the display panel of this disclosure.
[0039] Figure 3This is a partial cross-sectional view of one embodiment of the display panel of this disclosure.
[0040] Figure 4 This is a partial cross-sectional view of another embodiment of the display panel of this disclosure. Detailed Implementation
[0041] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.
[0042] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.
[0043] In this document, the row direction and column direction are two intersecting directions. In the accompanying drawings of this disclosure, the row direction is horizontal and the column direction is vertical, and they are perpendicular to each other. However, this is not a limitation; the row direction and column direction can also be non-perpendicular. Furthermore, those skilled in the art will understand that as the display panel rotates, the actual orientation of the row direction and column direction may change, but their relative positions remain unchanged.
[0044] In this article, the "overlap" of features A and B means that the orthographic projection of feature A on a plane and the orthographic projection of feature B on the same plane at least partially coincide; the plane can be the surface of a drive backplate, a first substrate, a second substrate, etc., or other planes.
[0045] The transistor described in this article includes a gate, a first terminal, and a second terminal. The conduction and cutoff between the first and second terminals can be achieved by controlling the voltage of the gate. The first terminal can be the source, and the second terminal can be the drain; of course, the first terminal can also be the drain, and the second terminal can also be the source. Specifically, if the input signal is from the first terminal, then the first terminal is the source, and the second terminal is the drain; if the input signal is from the second terminal, then the second terminal is the source, and the first terminal is the drain. In other words, the source and drain can be interchanged depending on the change in the input signal.
[0046] For a P-type transistor, when the gate receives a high level, both terminals are off; when the gate receives a low level, both terminals are on. For an N-type transistor, when the gate receives a high level, both terminals are on; when the gate receives a low level, both terminals are off.
[0047] like Figure 1 As shown, this disclosure provides a display panel that may include a display area AA and a peripheral area WA located outside the display area AA. The peripheral area WA may be a continuous annular area surrounding the display area AA, or it may be a discontinuous area surrounding the display area AA.
[0048] like Figure 3 and Figure 4 As shown, the display panel may include a driving backplate 1 and a plurality of light-emitting devices 2 disposed on one side of the driving backplate 1. Each light-emitting device 2 is arranged in an array along the row and column directions. The light-emitting devices 2 can be driven to emit light by the driving circuit in the driving backplate 1 to display images.
[0049] The light-emitting device 2 can be located within the display area AA. It can be an OLED (organic light-emitting diode) using organic light-emitting materials; or an LED (light-emitting diode) using inorganic light-emitting materials, such as Micro LED (micron light-emitting diode) and Mini LED (sub-millimeter light-emitting diode); or a QLED (quantum dot diode), etc. The specific structure of the light-emitting device 2 is not specifically limited here, as long as it can display images.
[0050] like Figure 3 and Figure 4 As shown, taking an OLED as an example, the light-emitting device 2 may include a first electrode 21, a light-emitting layer 22, and a second electrode 23 stacked sequentially along a direction away from the driving backplate 1. By applying an electrical signal to the first electrode 21 and the second electrode 23, the light-emitting layer 22 can be excited to emit light. The specific light-emitting principle will not be detailed here. At the same time, in order to define the range of the light-emitting device 2, the display panel may also include a pixel definition layer 3, which may be disposed on the same surface of the driving backplate 1 as the first electrode 21, and has pixel openings that expose each first electrode 21. The light-emitting layer 22 and the second electrode 23 may be stacked with the first electrode 21 within the pixel openings to form the light-emitting device 2. That is to say, the first electrode 21, the light-emitting layer 22, and the second electrode 23 within the pixel openings can constitute a light-emitting device 2, and the range of the light-emitting device 2 is the range of the pixel openings.
[0051] The driving circuit may include pixel circuits located within the display area AA and peripheral circuits located in the peripheral area WA. The pixel circuits can be arrayed along the row and column directions. One pixel circuit can be connected to the first electrode 21 of one light-emitting device 2, and a row of pixel circuits can be connected to the first electrode 21 of each of the light-emitting devices 2 in that row. Of course, the same pixel circuit can also be connected to the first electrodes 21 of multiple light-emitting devices 2. Furthermore, some pixel circuits may be located in the peripheral area WA. The pixel circuits can be 3T1C, 7T1C, etc., as long as they can drive the light-emitting device 2 to emit light; their structure is not specifically limited here. nTmC indicates that one pixel circuit includes n transistors (represented by the letter "T") and m capacitors (represented by the letter "C"). The number of pixel circuits can be the same as the number of light-emitting devices 2, and they are connected one-to-one with each light-emitting device 2. Of course, the same pixel circuit can also connect to multiple light-emitting devices 2; this is not specifically limited here.
[0052] The peripheral circuit can be connected to the light-emitting device 2 via the pixel circuit. The pixel circuit applies a first power signal VDD1 to the first electrode 21 of the light-emitting device 2. Conversely, the peripheral circuit can also be connected to the second electrode 23 of the light-emitting device 2 and apply a second power signal VSS1 to the second electrode 23. The pixel circuit can control the current flowing through the light-emitting device 2, thereby controlling the brightness of the light-emitting device 2. The peripheral circuit may include at least one gate driving circuit and a light-emitting control circuit, etc. Both the gate driving circuit and the light-emitting control circuit include multiple cascaded shift register units. The signal output from one shift register unit can control at least one row of pixel circuits.
[0053] The following example uses a single pixel circuit for illustration:
[0054] like Figure 2 As shown, the pixel circuit may include a driving transistor T1, a writing circuit, and a storage circuit. The first electrode of the driving transistor T1 receives a first power supply signal VDD1, and the second electrode of the driving transistor T1 is connected to the first electrode 21 of a light-emitting device 2. The second electrode 23 of the light-emitting device receives a second power supply signal VSS1. The writing circuit is connected to the gate of the driving transistor T1 and is used to transmit a data signal Data to the gate of the driving transistor T1 in response to a scan signal Gate1. The storage circuit is connected to the gate and the second electrode of the driving transistor T1 and can store the voltage of the data signal Data. The first power supply signal VDD1 and the second power supply signal VSS1 are constant voltage signals. By controlling the voltage of the data signal Data, the driving transistor T1 can be turned on, thereby controlling the current through the light-emitting device 2, and thus controlling the brightness of the light-emitting device 2.
[0055] like Figure 2As shown, in some embodiments of this disclosure, the writing circuit may include a writing transistor T2, and the storage circuit includes a storage capacitor Cst. The first terminal of the writing transistor T2 is used to receive the data signal Data, and the second terminal of the writing transistor T2 is connected to the gate of the driving transistor T1. The gate of the writing transistor T2 is used to receive a scan signal. The first plate of the storage capacitor Cst is connected to the gate of the driving transistor T1, and the second plate is connected to the second terminal of the driving transistor T1. The storage capacitor Cst can store the voltage of the data signal Data, and can still maintain the light emission of the light-emitting device 2 for a certain period of time after the writing transistor T2 is turned off.
[0056] By controlling the scan signal Gate1 to switch between high and low levels, the write transistor T2 can be turned on and off.
[0057] Furthermore, due to factors such as process and temperature, the threshold voltage and other electrical parameters of different driving transistors T1 vary, affecting the uniformity of the image. In some embodiments of this disclosure, the pixel circuit may further include a sensing transistor T3. The first terminal of the sensing transistor T3 is connected to the second terminal of the driving transistor T1 and may be connected to the S node. The second terminal of the sensing transistor T3 is used to output a sensing signal SL, which is the signal acquired from the second terminal of the driving transistor T1. The gate of the sensing transistor T3 is used to receive a sensing control signal Gate2 and can be turned on and off under the control of the sensing control signal Gate2. The sensing transistor T3 can acquire the signal from the second terminal of the driving transistor T1 and transmit the signal to the driving chip. The driving chip can determine compensation data based on the difference in the signal and adjust the data signal Data according to the compensation data to achieve external compensation, which is beneficial to improving the uniformity of the brightness of the light-emitting device 2.
[0058] Furthermore, to facilitate signal transmission, the drive backplane 1 may include power lines, scan lines, a first power bus, a second power bus, sensing control lines, and sensing lines, wherein:
[0059] The first power bus and the second power bus are located in the peripheral area WA. The first power bus is used to transmit the first power signal VDD1, and the second power bus is used to transmit the second power signal VSS1.
[0060] The power line may extend along the column direction and is at least partially located in the display area AA. The power line may be connected to the first terminal of the driving transistor T1. The power line is connected to a first power bus, thereby transmitting a first power signal VDD1 to the driving transistor T1 via the first power bus and the power line.
[0061] The second electrode 23 of each light-emitting device 2 may be located in the same continuous film layer, and the film layer may extend to the peripheral region WA and be connected to the second power bus so as to transmit the second power signal VSS1 to the second electrode 23.
[0062] The scan line can extend along the row direction and is at least partially located within the display area AA, and is connected to the gate of the write transistor T2, so that the scan signal Gate1 can be transmitted to the write transistor T2.
[0063] At least a portion of the sensing control line is located within the display area AA and connected to the gate of the sensing transistor T3, enabling the transmission of the sensing control signal Gate2 to the writing transistor T2. In some embodiments, the sensing control line and the scan line may be the same trace, and the sensing control signal Gate2 and the scan signal Gate1 may be the same signal. At least a portion of the sensing line is located within the display area AA and connected to the second terminal of the sensing transistor T3, and the sensing line may be connected to a driver chip for transmitting the acquired signal from the second terminal of the driving transistor T1 to the driver chip.
[0064] For a pixel circuit, the driving transistor T1 can be turned on by the data signal Data. Under the action of the first power signal VDD1 and the second power signal VSS1, a current is generated through the light-emitting device 2, causing the light-emitting device 2 connected to the driving transistor T1 to emit light, thereby realizing the display of an image. In this process, the voltage of the data signal Data is positively correlated with the voltage of the second terminal of the driving transistor T1, and the voltage of the second terminal of the driving transistor T1 is positively correlated with the current of the light-emitting device 2. This current is positively correlated with the brightness of the light-emitting device and the heat generated by the light emission, so that the voltage of the data signal Data is positively correlated with the brightness and heat of the light-emitting device.
[0065] The inventors discovered that when a display panel displays an image, there are significant differences in brightness and color across different areas. Consequently, the current of the light-emitting devices in these areas varies considerably, leading to significant temperature differences. These temperature variations affect the electrical characteristics of transistors and alter the efficiency of the light-emitting devices, causing localized brightness deviations and resulting in image anomalies. For example, bright areas have high temperatures, and these high-temperature areas are prone to image retention, particularly noticeable around logos. To address this, the temperature of the display panel can be detected, and different areas can be cooled to varying degrees to improve image uniformity. However, detecting the temperature of different areas of the display panel requires specialized equipment, which is costly. Furthermore, determining the cooling strategy based on temperature detection is time-sensitive and lacks accuracy.
[0066] Based on the above analysis, the inventors propose a solution for more precise real-time cooling of the display panel, which is illustrated below:
[0067] like Figure 3 and Figure 4 As shown, the display panel may further include a temperature control substrate 4, which may be disposed on the side of the driving backplate 1 away from the light-emitting device 2, such that the driving backplate 1 is located between the light-emitting device 2 and the temperature control substrate 4. The temperature control substrate 4 includes a plurality of temperature control elements 40, each temperature control element 40 having a cooling end and a heat dissipation end. The cooling end and heat dissipation end of any temperature control element 40 may be distributed in a direction away from the driving backplate 1, that is, the cooling end is closer to the driving backplate 1, and the heat dissipation end is further away from the driving backplate 1. The cooling end of any temperature control element 40 can cool down its corresponding area in the display panel, and the heat dissipation end can dissipate heat.
[0068] The temperature control element 40 can receive a third power signal VDD2 and a fourth power signal VSS2, and in order to control the cooling capacity of the temperature control element 40 in real time, such as Figure 2 As shown, in some embodiments of this disclosure, the pixel circuit may further include a temperature control circuit. The temperature control element 40 can receive a third power supply signal VDD2 through the temperature control circuit, thereby controlling the voltage and current of the temperature control element 40. Simultaneously, the temperature control circuit can be connected to the second electrode of the driving transistor T1 and connected to the S node, and is turned on or off under the control of the voltage of the signal of the second electrode 23. This allows the temperature control element 40 to be controlled by the signal of the second electrode of the driving transistor T1 to adjust the cooling capacity. The cooling capacity is positively correlated with the voltage of the signal of the second electrode, that is, positively correlated with the voltage of the S node. As mentioned above, the voltage of the signal of the second electrode is controlled by the data voltage and is positively correlated with the data voltage, thereby being positively correlated with the current, brightness, and temperature of the light-emitting device. This makes the cooling capacity of the temperature control element 40 positively correlated with the voltage of the data signal Data. The cooling capacity of the temperature control element 40 can change with the change of the voltage of the data signal Data, thereby realizing real-time adjustment of the cooling capacity. Furthermore, it eliminates the need for a dedicated detection device to detect the temperature of different areas, which is beneficial for simplifying the structure, reducing costs, and improving the accuracy and timeliness of temperature control.
[0069] When the display panel displays an image, the higher the brightness of the area, the greater the cooling capacity of the temperature control element 40, resulting in a stronger cooling effect; conversely, the lower the brightness of the area, the less cooling capacity of the temperature control element 40, resulting in a weaker cooling effect. This ensures a more uniform temperature across areas of different brightness, preventing brightness deviations from the standard due to excessively high local temperatures and reducing or eliminating localized afterimages. Furthermore, the cooling capacity of the temperature control element 40 can be adjusted in real time via the data signal (Data), eliminating the need to specifically detect the temperature of the light-emitting device and calculate the cooling capacity, making cooling more timely and precise.
[0070] The temperature control substrate 4 is described below by way of example:
[0071] like Figure 3 and Figure 4 As shown, the temperature control substrate 4 may include a first substrate 41 and a second substrate 42, with the second substrate 42 located between the first substrate 41 and the drive backplate 1. The first substrate 41 and the second substrate 42 may be made of insulating and thermally conductive materials such as ceramic. A temperature control element 40 may be disposed between the first substrate 41 and the second substrate 42. The temperature control element 40 may be a semiconductor cooler, which is based on the Peltier effect and utilizes a thermocouple to convert between thermal energy and electrical energy. The aforementioned cooling capacity may be the heat absorbed by the temperature control element 40 from the outside, i.e., the heat of the Peltier effect.
[0072] The temperature control element 40 may include two interconnected thermocouples. Specifically, a temperature control element 40 may include a first connecting electrode 43, a second connecting electrode 44, a connecting bridge 45, a first thermocouple 46, and a second thermocouple 47, wherein:
[0073] The first thermocouple 46 and the second thermocouple 47 can be columnar structures, extending perpendicularly to the first substrate 41 and the second substrate 42, and spaced apart in a direction parallel to the first substrate 41 and the second substrate 42. The first thermocouple 46 can be an N-type semiconductor, and the second thermocouple 47 can be a P-type semiconductor. For example, both the first thermocouple 46 and the second thermocouple 47 can be made of bismuth telluride (Bi2Te3) alloy or other semiconductor materials with thermoelectric properties, and can be doped to obtain P-type semiconductors (which may be doped with impurities such as boron) and N-type semiconductors (which may be doped with impurities such as phosphorus), respectively.
[0074] The first connecting electrode 43 and the second connecting electrode 44 can be disposed on the side of the first electrode 46 and the second electrode 47 near the first substrate 41. They are spaced apart and are different regions of the same conductive film layer, and therefore can be formed simultaneously by processes such as photolithography or electroplating. Simultaneously, the first connecting electrode 43 is connected to the first electrode 46, and the second connecting electrode 44 is connected to the second electrode 47. For example, the end of the first electrode 46 near the first substrate 41 can be directly stacked on the surface of the first connecting electrode 43 away from the first substrate 41, and the end of the second electrode 47 near the first substrate 41 can be directly stacked on the surface of the second connecting electrode 44 away from the first substrate 41. The orthographic projection of the first electrode 46 on the first substrate 41 can be located within the orthographic projection of the first connecting electrode 43 on the first substrate 41, and the orthographic projection of the second electrode 47 on the first substrate 41 can be located within the orthographic projection of the second connecting electrode 44 on the first substrate 41.
[0075] The connecting bridge 45 may be disposed on the side of the first thermocouple 46 and the second thermocouple 47 near the second substrate 42, and connect the first thermocouple 46 and the second thermocouple 47; the ends of the first thermocouple 46 and the second thermocouple 47 near the second substrate 42 may be directly stacked on the surface of the connecting bridge 45 away from the second substrate 42. The orthographic projections of the first thermocouple 46 and the second thermocouple 47 on the second substrate 42 may be located within the orthographic projection of the connecting bridge 45 on the second substrate 42.
[0076] The first connecting electrode 43, the second connecting electrode 44, and the connecting bridge 45 can be made of conductive materials or alloys such as copper, aluminum, and titanium, and the first connecting electrode 43, the second connecting electrode 44, and the connecting bridge 45 can be made of the same material and have the same thickness.
[0077] The ends of the first thermocouple 46 and the second thermocouple 47 near the connecting bridge 45, which is the cooling end of the temperature control element 40, can absorb the heat from the driving backplate 1 through the second substrate 42; the ends of the first thermocouple 46 and the second thermocouple 47 near the first connecting electrode 43 and the second connecting electrode 44, which is the heat dissipation end of the temperature control element 40, can dissipate heat through the first substrate 41.
[0078] It should be noted that the cooling end and heat dissipation end of the semiconductor cooler are affected by the voltages of the third power signal VDD2 and the fourth power signal VSS2. If the voltages of the third power signal VDD2 and the fourth power signal VSS2 are interchanged, the cooling end and the heat dissipation end will be interchanged. This disclosure should ensure that the cooling end is the end closer to the drive backplate 1.
[0079] Furthermore, such as Figure 4 As shown, in some embodiments of this disclosure, the temperature control substrate 4 further includes an insulating filler layer 48, which can be made of inorganic materials such as silicon nitride, or organic materials such as resin; no special limitation is made here, as long as it provides insulation. The insulating filler material can be filled between the first substrate 41 and the second substrate 42. The first thermocouple 46 and the second thermocouple 47 of the temperature control element 40 can be embedded in the insulating filler layer 48. The insulating filler material provides support between the first substrate 41 and the second substrate 42 and defines the positions of the first thermocouple 46 and the second thermocouple 47. Of course, as... Figure 3 As shown, in other embodiments of this disclosure, insulating filler material may not be provided.
[0080] like Figure 3 and Figure 4As shown, in order to improve heat dissipation efficiency, in some embodiments of this disclosure, the temperature control substrate 4 has a plurality of temperature control elements 40, that is, no less than two; each temperature control element 40 can be divided into multiple temperature control units, and a temperature control unit may include multiple temperature control elements 40. The temperature control elements 40 of the same temperature control unit are connected in series. That is, in a temperature control unit with m temperature control elements 40, the second connection electrode 44 of the (n-1)th temperature control element 40 is connected to the first connection electrode 43 of the nth temperature control element 40 or adopts an integrated structure. The first connection electrode 43 of the first temperature control element 40 serves as the first power supply terminal of the temperature control unit and can be connected to the temperature control circuit. The second connection electrode 44 of the mth temperature control element 40 serves as the second power supply terminal of the temperature control unit and can be used to receive the fourth power signal VSS2; m≥n≥2, where n and m are both positive integers.
[0081] In some embodiments, the temperature control elements 40 of a temperature control unit can also be connected in parallel, that is, the first connection electrode 43 of each temperature control element 40 is connected and connected to the same temperature control circuit, and the second connection electrode 44 of each temperature control element 40 is connected and used to receive the fourth power signal VSS2. Of course, in some embodiments, the temperature control elements 40 of a temperature control unit can also be mixed, that is, series and parallel connections exist simultaneously.
[0082] In some embodiments of this disclosure, a temperature control unit may overlap with a pixel circuit to cool the area corresponding to the pixel circuit. However, this disclosure does not limit all transistors and capacitors of the pixel circuit to overlap with the temperature control unit; at least the driving transistor T1 may overlap with the temperature control unit. Simultaneously, a light-emitting device may overlap with a temperature control unit to cool the area corresponding to the light-emitting device.
[0083] In some embodiments of this disclosure, such as Figures 2-4 As shown, the temperature control circuit may include a temperature control transistor T4. The first terminal of the temperature control transistor T4 is used to receive a third power supply signal VDD2. The second terminal of the temperature control transistor T4 is connected to the first connection electrode 43 of a temperature control element 40. The gate of the temperature control transistor T4 is connected to the second terminal of the driving transistor T1. Simultaneously, different temperature control units can be independently configured, meaning different temperature control units are controlled by different temperature control circuits. The second terminal of one temperature control transistor T4 can be connected to the first connection electrode 43 of a temperature control element 40 within that temperature control unit.
[0084] In some embodiments of this disclosure, the second power signal VSS1 and the fourth power signal VSS2 can be the same signal, thereby allowing simultaneous transmission of the second power signal VSS1 and the fourth power signal VSS2 to the temperature control element 40 and the light-emitting device via the same trace, simplifying the circuit structure. For example, the signal transmitted by the aforementioned second power bus is both the second power signal VSS1 and the fourth power signal VSS2. At least one second connection electrode 44 of the temperature control element 40 can be connected to the second power bus to receive the fourth power signal VSS2, and for a temperature control unit employing series temperature control elements 40, the second power terminal is connected to the second power bus. Furthermore, since the second power terminals of each temperature control unit are all connected to the second power bus, the second power terminals of each temperature control unit can be integrated into a single structure.
[0085] The structure of the drive backplane 1 is illustrated below:
[0086] like Figure 3 and Figure 4 As shown, the driving backplane 1 includes a semiconductor layer 11, a gate insulating layer 12, a gate layer 13, an interlayer dielectric layer 14, and a planarization layer 16, wherein:
[0087] The semiconductor layer 11 may be disposed on the side of the second substrate 42 away from the first substrate 41, and includes the active portions of the driving transistor T1, the writing transistor T2, the sensing transistor T3, and the temperature control transistor T4. The specific pattern is not particularly limited here. The material of the semiconductor layer 11 may be polycrystalline silicon or metal oxides such as IGZO, and is not particularly limited here.
[0088] The gate insulating layer 12 covers at least a portion of the semiconductor layer 11, and its material includes inorganic insulating materials such as silicon nitride, silicon oxide, and silicon oxynitride.
[0089] The gate layer 13 may be disposed on the surface of the gate insulating layer 12 away from the first substrate 41, and includes the gates of the driving transistor T1, the writing transistor T2, the sensing transistor T3 and the temperature control transistor T4; the gate layer 13 may be made of metal or alloy materials such as molybdenum or copper, as long as it can conduct electricity.
[0090] The interlayer dielectric layer 14 may cover the gate layer 13, and its material includes inorganic insulating materials such as silicon nitride, silicon oxide, and silicon oxynitride.
[0091] The source / drain layer 15 can be disposed on the surface of the interlayer dielectric layer 14 away from the first substrate 41, and is used to connect transistors and capacitors in the pixel circuit. The first electrode of the storage capacitor Cst can be located on the gate layer 13, and the second electrode can be located on the source / drain layer 15. At the same time, the source / drain layer 15 can also be used to connect the second electrode of the driving transistor T1 and the first connection electrode 43 of the temperature control element 40.
[0092] The planarization layer 16 may cover the source / drain layer 15, and may be made of organic insulating materials such as resin to achieve planarization. The first electrode 21 and the pixel definition layer 3 of the light-emitting device may be disposed on the surface of the planarization layer 16 away from the first substrate 41.
[0093] In some embodiments of this disclosure, the drive backplane 1 may further include a buffer layer 17, which may be disposed on the side of the second substrate 42 away from the first substrate 41, and the semiconductor layer 11 may be disposed on the surface of the buffer layer 17 away from the first substrate 41. The buffer layer 17 may be made of inorganic insulating materials such as silicon nitride, silicon oxide, or silicon oxynitride.
[0094] Furthermore, in some embodiments, the drive backplate 1 may also include a substrate that can be attached to the surface of the second substrate 42 away from the first substrate 41, and the buffer layer 17 and the semiconductor layer 11 may be disposed on the side of the substrate away from the first substrate 41. Of course, in some embodiments, a substrate may not be provided, and the buffer layer 17 may be directly disposed on the surface of the second substrate 42 away from the first substrate 41.
[0095] In some embodiments, the display panel may also include an encapsulation layer 5, which may cover each light-emitting device 2. The encapsulation layer 5 may be thin-film encapsulation or other methods, as long as it can prevent external moisture and oxygen from corroding the light-emitting devices 2.
[0096] In some embodiments of this disclosure, the third power signal VDD2 and the first power signal VDD1 are different signals, and their voltages may be different. To facilitate the transmission of the third power signal VDD2, the drive backplane 1 may further include a third power bus located in the peripheral area WA, and the third power bus can transmit the third power signal VDD2. The first terminal of the temperature control transistor T4 may be connected to the third power bus.
[0097] This disclosure also provides a display device, which may include a display panel. The display panel may be any of the display panels described in the above embodiments, and its specific structure and beneficial effects will not be repeated here. The display device may be a mobile phone, a television, a tablet computer, or a VR (Virtual Reality) device, a smartwatch, or other wearable device, which will not be listed here.
[0098] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.
Claims
1. A display panel, characterized in that, The device includes a driving backplate, a light-emitting device, and a temperature control substrate. The driving backplate is disposed between the light-emitting device and the temperature control substrate. The temperature control substrate includes a temperature control element, which has a cooling end and a heat dissipation end distributed in a direction away from the driving backplate. The driving backplane includes a pixel circuit, which includes a driving transistor, a writing circuit, a storage circuit, and a temperature control circuit. The first electrode of the driving transistor is used to receive a first power signal, the second electrode of the driving transistor is connected to the first electrode of the light-emitting device, and the second electrode of the light-emitting device is used to receive a second power signal; the writing circuit is connected to the gate of the driving transistor and is used to transmit a data signal to the gate of the driving transistor in response to a scan signal. The storage circuit is connected to the gate and the second electrode of the driving transistor; The temperature control circuit is used to receive a third power signal and is connected to the temperature control element and the second terminal of the driving transistor. The temperature control element is also used to receive a fourth power signal. The cooling capacity of the temperature control element is positively correlated with the voltage of the data signal.
2. The display panel according to claim 1, characterized in that, The temperature control substrate includes a first substrate and a second substrate arranged sequentially along a direction close to the drive back plate, and the temperature control element is disposed between the first substrate and the second substrate. The temperature control element is a thermocouple, and the temperature control element includes a first connecting electrode, a second connecting electrode, a connecting bridge, a first thermocouple using an N-type semiconductor and a second thermocouple using a P-type semiconductor. The first connecting electrode and the second connecting electrode are disposed on the side of the first thermocouple and the second thermocouple close to the first substrate, and the first connecting electrode is connected to the first thermocouple, and the second connecting electrode is connected to the second thermocouple; the connecting bridge is disposed on the side of the first thermocouple and the second thermocouple close to the second substrate, and connects the first thermocouple and the second thermocouple.
3. The display panel according to claim 2, characterized in that, The temperature control substrate includes multiple temperature control units, one of which overlaps with a pixel circuit and a light-emitting device; each temperature control unit includes multiple temperature control elements, and the temperature control elements of the same temperature control unit are connected in series.
4. The display panel according to claim 2, characterized in that, The writing circuit includes a writing transistor, the temperature control circuit includes a temperature control transistor, and the storage circuit includes a storage capacitor; The first terminal of the write transistor is used to receive the data signal, the second terminal of the write transistor is connected to the gate of the drive transistor, and the gate of the write transistor is used to receive the scan signal; The first plate of the storage capacitor is connected to the gate of the driving transistor, and the second plate is connected to the second terminal of the driving transistor. The first electrode of the temperature control transistor is used to receive the third power supply signal, the second electrode of the temperature control transistor is connected to the first connection electrode of the temperature control element, and the gate of the temperature control transistor is connected to the second electrode of the driving transistor. The pixel circuit also includes a sensing transistor, the first terminal of which is connected to the second terminal of the driving transistor. The second terminal of the sensing transistor is used to output the signal of the second terminal of the driving transistor, and the gate of the sensing transistor is used to receive a sensing control signal.
5. The display panel according to claim 4, characterized in that, The drive backplate includes: A semiconductor layer is disposed on the side of the second substrate away from the first substrate, and includes the active portions of the driving transistor, the writing transistor, the sensing transistor, and the temperature control transistor; A gate insulating layer covering at least a portion of the semiconductor layer; A gate layer is disposed on the surface of the gate insulating layer away from the first substrate, and includes the gates of the driving transistor, the writing transistor, the sensing transistor, and the temperature control transistor; Interlayer dielectric layer, covering the gate layer; The source / drain layer is disposed on the surface of the interlayer dielectric layer away from the first substrate; A planarization layer covers the source / drain layer; the light-emitting device is disposed on the surface of the planarization layer away from the first substrate.
6. The display panel according to claim 4, characterized in that, The second power signal and the fourth power signal are the same.
7. The display panel according to claim 6, characterized in that, The display panel has a display area and a peripheral area located outside the display area; the driving backplate includes a power line, a first power bus and a second power bus; the first power bus is used to transmit the first power signal, and the second power bus is used to transmit the second power signal and the fourth power signal; The power line is at least partially located in the display area and connected to the first electrode of the driving transistor; the first power bus and the second power bus are located in the peripheral area, and the power line is connected to the first power bus, while the second electrode of the light-emitting device and the second connection electrode of the temperature control element are connected to the second power bus.
8. The display panel according to claim 7, characterized in that, The drive backplane also includes a third power bus located in the peripheral area. The third power bus is used to transmit the third power signal, and the first terminal of the temperature control transistor is connected to the third power bus.
9. The display panel according to claim 2, characterized in that, The temperature control substrate also includes: An insulating filler layer is filled between the first substrate and the second substrate; the first and second thermocouples of the temperature control element are embedded in the insulating filler layer.
10. A display device, characterized in that, Includes the display panel as described in any one of claims 1-9.